Automatic transmission



May 27, 1952 s. s. cRoss 'r A1.

AUTOMATIC TRANSMISSION 2 SHEETS-SHEET l Filed Jan. 28, 1950 3 nve n tors SHERMAN 1005s AIVD APL /f 4. dejar i May 27, 1952 s. s. cRoss Er AL 2,597,854

AUTOMATIC TRANSMISSION Filed Jan. 28, 195o 2 SHEETS-SHEET 2 :inventors Patented May 27, 1952 2,597,854 vAUTOMATIC TRANSMISSION Sherman S. Cross, Cuyahoga Falls, and Arlie A. Cross, Stow, Ohio Application January 28, 1950, Serial No. 141,020

(Cl. 'I4-752) 17 Claims. l

This invention relates to an automatic transmission and, in particular, to a transmission in which torque-modifying arrangements are automatically cut in or out out of the system by speed-responsive devices.

, In the presently popular, light vehicles, such asmotor bikes, scooters, and the like, conventional gear shift systems are cumbersome and expensive, and the demand is for a light, compact, self-acting torque modifier which can be easily installed and easily removed for maintenance or replacement.

It is, therefore, an object of the invention to provide a torque-modifying transmission unit which is automatically responsive to speed to vary the torque. A further object is to provide a device of this nature which is simple of structure, light in weight, compact, and economical of manufacture. y

These and other ends, whichV will be apparent to those skilled in the art, are attained by the invention, preferred forms of which are described in the following specification and illustratedin the drawings, in which:

Fig. 1 is an axial sectional view of one embodiment of the transmission unit,

Fig. 2 is a sectional -view taken along the staggered line 2-2 of Fig. 1,

Fig. 3 is a sectional view taken on the line 3 3 of Fig. 1, and w Fig. 4 is an axial sectional view of a modified embodiment of the transmission unit.

Referring to the drawings by characters of reference, there is shown, in Fig. l, a ring-shaped housing I, having end closure plates 2 and 3 secured by screws 4 and 6. End plate 3 has a central ange 1 defining a circular opening in which is fitted a bearing sleeve 8. A sleeve 9, fitted in ybearing sleeve 8 for rotation therein, has a star wheel portion inwardly of plate 3, comprising a hub II and radial spokes I2. A thrust bearing disk I3 is provided between hub II and plate 3.

` A pulley I4, keyed to sleeve 9, at I6, serves as the power input when connected to the motor by a Weights 2l are normally held in their radially inner positions, away from wedging contact with cage I8. by'means of a helical, garter spring 24, received in grooves 26 in the outer faces of the weights. The latter will have characteristics appropriate to the input speed at which it is desired to connect the low gearing, which, as will be shown, occurs when cage I8 is picked up by weights 2 I. Hub II has an annular rib 21 adapted to receive V-grooves 28 in the inner edges of weights 2| to maintain them centrally of the walls of cage I8 when in their inner position.

Cage I8 has an internal hub 29 secured as by welding in an opening in the cage wall opposite the wall having opening I1. Hub 29 is mounted on a sleeve 3I rotatably mounted on an output shaft 32, hub 29 being secured to sleeve 3I by a key 33.

Output shaft 32 is the central element of the system and carries, at one end, a gear 34 having a hub 36 secured to the shaft by a pin 31 and rotatable in a bearing sleeve 38 secured in an internal, blind bore of a central boss 39 on housing plate 2. At itsother end, shaft 32 has an enlarged section 4I rotatably mounted in a bearing sleeve 42 carried in sleeve 9. A thrust bearing washer 43 is located at the shoulder defined by enlarged portion 4I of the shaft and abuts the ends of sleeves 9 and 3|.

A second weight cage, indicated generally by the numeral 44, has a circular wall element 46 with a central hub 41, which is carried in rotation with sleeve 3I by the same key 33 which carries hub 29 of cage I8. Thus, cage I8 and cage element 46 rotate in unison. The opposite wall element 48 of cage 44 has an inwardly extending hub 49 which rotates on hub 41 of element 46.

Six sector-shaped weights 5I, contained between cage elements 46, 48 are free to slide outwardly, against the pressure of a surrounding, helical garter spring 52, and have tapering sides 53 adapted to engage correspondingly tapered inner walls of cage elements 46, 48 so that element 48 will be carried in rotation by element 46. Rotation is imparted to Weights 5I by pins 54 carried by cage element 46 and engaging in radial slots 56 in the weights. Spring 52 is accommodated in circumferential grooves 51 in the weights.

Formed on the end of, or otherwise secured to the end of sleeve 3l, is a gear 58 and, adjacent thereto, is a large wheel 59 having a central bearing sleeve 60 mounted for rotation on output shaft 32. Wheel 59. serves to carry reduction gearing which transmits the drive from gear 58 to gear 34 on output shaft 32. For this purpose, a series arenaria 5 iianged, marginalV portion |23 of member |2| is thus urged against the outer one of a series of i friction plates |24, alternate plates .of vwhich are is urged to its innermost position by springV H0,

fianges |23 of member |2| are pressing against friction plates |24; Wheel 59 isA therefore held against rotation and the reduction gearing 6s, 6 I, 34 comes into play as in the-case of Fig. l;

When the speed is sufficient for Weights |03 to pick up disk the latter moves outwardly carrying member |2| with it to relieve the pressure on plates |24, and pins ||2 carry wheel 59' in rotation, with the whole system rotating as a unit, as in the case of Fig. 1.

Obviously, the form and arrangement of the weight cages of Fig. 4 may be substituted for those of Fig. 1. Likewise, the pressure plates |24 and associated elements may be substituted for the over-running clutch of Fig. 1.

It is to be particularly noted that in using pressure plates such as |24 or equivalent, instead of an over-running clutch, the transmission, as a whole, is operable in either direction of rotation.

Whereas certain embodiments of the invention have been shown and described, the invention is not limited thereby since changes in the size, shape, and arrangement, for instance of the various parts may be made without, however, departing from the spirit or scope of the appended claims.

What is claimed is:

1. A power transmission comprising a first series of centrifugal weights. means enclosing said rst series and adapted to be rotated thereby, a gear connected to said means for rotation therewith, a wheel having a planetary gear meshing with the first-mentioned gear, a second planetary gear, an output shaft, a gear on said output shaft meshing with said second planetary gear, said gears being of a size to constitute a reduction in rotational speed between said firstmentioned means and said output shaft, means to prevent rotation of said wheel in one direction, a second series of centrifugal weights, means enclosing said second series and comprising"sepa rately rotatable sections, one of said sections carrying said second series of weights and having a connection with the first mentioned means to be rotated thereby, the other of said sections adapted for rotation by said second series of weights, and the said other of saidsections and said wheel being connected so as to rotate'in unison. l

2. A device as in claim 1, said means to prevent rotation comprising an over-running clutch.

3. A device as in claim 1, said means to prevent rotation comprising a. friction means having an operating spring connected to said other of said sections and said spring movable with the latter into and out of engagement with said friction means.

4. In a device as in claim 1, a housing journaling said output shaft at opposite ends and the elements of the transmission being supported on and rotatable about said output shaft.

5. A device as in claim 1, said first-mentioned means being a unitary structure and keyed for .Sad weights..

` common rotationwith said one .of said sections. y

6. A device as ,in claiml, said mst-mentioned means comprising a normally freely rotatableelement, engageableubysaid rst series of weights,

and said yconnection comprising friction plates between the freely rotatable element and said 27.- Avdevice as invclaim,1, said "weights of one oneof said sections. f y

series having` aslant surface on` one side only and theenclosing means of said series having a Wall slantedtocomplement the slant surface of 8. A device as in claim 1, said connection comprising. -frictionplatea and said first-mentioned means comprising "a, wedge element engageable by the weights of said first series and movable axially thereby to press on said friction plates.

9. A power transmission comprising a housing, an output shaft journaled in opposite walls of said housing and extending therefrom, an input sleeve rotatable on said shaft, a first cage rotatable on said shaft, spring-pressed weights in said cage adapted to move radially outwardly to lgrip the first cage and rotate it, driving means between said input sleeve and said Weights to revolve the weights about the shaft, a Wheel rotatable on said shaft, a first gear on one side of said wheel, rotatable on the shaft and connected to said first cage for rotation therewith, a second gear on the other side of said wheel and keyed to said shaft. a pair of coaxially arranged gears carried by said Wheel and engaging the said first and second gears, respectively, means to prevent rotation of said wheel in one direction, a second cage rotatable about said shaft and having an element with a driving connection from said first cage and centrifugal weights keyed to said element and slidable radially thereof, said second cage having a further element rotatable about said shaft and engageable by the weights in said second cage to be rotated thereby, and means connecting said second element and said wheel whereby the Wheel is rotated by the said second element.

10. A device as in claim 9, said first cage having an axial opening, and said driving means comprising an element of said input sleeve extending within said opening and having keying means engaging the weights in the said first cage in a manner to permit radial movement of the weights.

11. A device as in claim 9, said first cage having independently rotatable parts, one of which is connected to said input sleeve, and keying means between said one of said parts and the weights in said first cage arranged to revolve the weights about the said shaft but permit movement of the weights radially of the shaft.

12. A device as in claim 9, the connection between said first gear and said first cage comprising a hub on the said first gear on which both said cages are mounted, and keying means between said first cage and said hub.

13. A device as in claim 12, the first-mentioned element of said second cage being also keyed to said hub.

14. A device as in claim 9, the connection between said first gear and said first cage comprising a hub on said first gear, on which said second cage is mounted, the first-mentioned element of said second cage being keyed to said hub.

15. A device as in claim 9, said first cage comprising an element adapted to be rotated by the weights in said first cage, frictional driving means between said element and the first-menemmen V ing and said wheel, means camedby theA lastfurther elemnt,V

1 S'. CRGSS.

8 REFERENCES CITED The. following references are of rm'zcardv in the le of thi-sV -paentzY UNlIED STATES. PATENTS Number Name Dette` 1,797,826 Gage V- Mar. 2.4:, 1931 1,349,177 'Dickson Mar. 15, 1932 1,902,050 Vincent v Mar. 2l, 1933 1,927,509: Waterhouse v Sept. 155i, 1933 2,022,689 4Rainsforvd Dec. 3, 1935 2,174,835. Ransford Y Oct. 3,v 1939 2500!? 63 Lowndes A-. Mar. 1,4, 1950 

